From patchwork Tue Oct 1 08:25:07 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fabrizio Castro X-Patchwork-Id: 11168169 X-Patchwork-Delegate: iwamatsu@nigauri.org Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E6CAE15AB for ; Tue, 1 Oct 2019 08:26:31 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id CF54121783 for ; Tue, 1 Oct 2019 08:26:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CF54121783 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bp.renesas.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=cip-dev-bounces@lists.cip-project.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 7E2567CED; Tue, 1 Oct 2019 08:26:10 +0000 (UTC) X-Original-To: cip-dev@lists.cip-project.org Delivered-To: cip-dev@mail.linuxfoundation.org Received: from smtp2.linuxfoundation.org (smtp2.linux-foundation.org [172.17.192.36]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 2ADF27CB3 for ; Tue, 1 Oct 2019 08:25:51 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from relmlie6.idc.renesas.com (relmlor2.renesas.com [210.160.252.172]) by smtp2.linuxfoundation.org (Postfix) with ESMTP id 168FA1DDC8 for ; Tue, 1 Oct 2019 08:25:49 +0000 (UTC) X-IronPort-AV: E=Sophos;i="5.64,570,1559487600"; d="scan'208";a="27778934" Received: from unknown (HELO relmlir6.idc.renesas.com) ([10.200.68.152]) by relmlie6.idc.renesas.com with ESMTP; 01 Oct 2019 17:25:49 +0900 Received: from fabrizio-dev.ree.adwin.renesas.com (unknown [10.226.36.196]) by relmlir6.idc.renesas.com (Postfix) with ESMTP id 0468841D9345; Tue, 1 Oct 2019 17:25:47 +0900 (JST) From: Fabrizio Castro To: cip-dev@lists.cip-project.org Date: Tue, 1 Oct 2019 09:25:07 +0100 Message-Id: <1569918331-6990-9-git-send-email-fabrizio.castro@bp.renesas.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1569918331-6990-1-git-send-email-fabrizio.castro@bp.renesas.com> References: <1569918331-6990-1-git-send-email-fabrizio.castro@bp.renesas.com> X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp2.linux-foundation.org Cc: Biju Das Subject: [cip-dev] [PATCH 4.19.y-cip 08/32] drm: rcar-du: Use LVDS PLL clock as dot clock when possible X-BeenThere: cip-dev@lists.cip-project.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: cip-dev-bounces@lists.cip-project.org Errors-To: cip-dev-bounces@lists.cip-project.org From: Laurent Pinchart commit b4734f43f3cadfaa423ce6aceb1e9faea07b8eb8 upstream. On selected SoCs, the DU can use the clock output by the LVDS encoder PLL as its input dot clock. This feature is optional, but on the D3 and E3 SoC it is often the only way to obtain a precise dot clock frequency, as the other available clocks (CPG-generated clock and external clock) usually have fixed rates. Add a DU model information field to describe which DU channels can use the LVDS PLL output clock as their input clock, and configure clock routing accordingly. This feature is available on H2, M2-W, M2-N, D3 and E3 SoCs, with D3 and E3 being the primary targets. It is left disabled in this commit, and will be enabled per-SoC after careful testing. At the hardware level, clock routing is configured at runtime in two steps, first selecting an internal dot clock between the LVDS PLL clock and the external DOTCLKIN clock, and then selecting between the internal dot clock and the CPG-generated clock. The first part requires stopping the whole DU group in order for the change to take effect, thus causing flickering on the screen. For this reason we currently hardcode the clock source to the LVDS PLL clock if available, and allow flicker-free selection of the external DOTCLKIN clock or CPG-generated clock otherwise. A more dynamic clock selection process can be implemented later if the need arises. Signed-off-by: Laurent Pinchart Tested-by: Jacopo Mondi Reviewed-by: Jacopo Mondi Signed-off-by: Fabrizio Castro --- drivers/gpu/drm/rcar-du/rcar_du_crtc.c | 8 +++++ drivers/gpu/drm/rcar-du/rcar_du_drv.h | 2 ++ drivers/gpu/drm/rcar-du/rcar_du_group.c | 64 +++++++++++++++++++++++++-------- 3 files changed, 59 insertions(+), 15 deletions(-) diff --git a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c index 57cdc5f..c330730 100644 --- a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c +++ b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c @@ -223,6 +223,14 @@ static void rcar_du_crtc_set_display_timing(struct rcar_du_crtc *rcrtc) rcar_du_group_write(rcrtc->group, DPLLCR, dpllcr); escr = ESCR_DCLKSEL_DCLKIN | div; + } else if (rcdu->info->lvds_clk_mask & BIT(rcrtc->index)) { + /* + * Use the LVDS PLL output as the dot clock when outputting to + * the LVDS encoder on an SoC that supports this clock routing + * option. We use the clock directly in that case, without any + * additional divider. + */ + escr = ESCR_DCLKSEL_DCLKIN; } else { unsigned long clk; u32 div; diff --git a/drivers/gpu/drm/rcar-du/rcar_du_drv.h b/drivers/gpu/drm/rcar-du/rcar_du_drv.h index a6e6316..7edf4a9 100644 --- a/drivers/gpu/drm/rcar-du/rcar_du_drv.h +++ b/drivers/gpu/drm/rcar-du/rcar_du_drv.h @@ -58,6 +58,7 @@ struct rcar_du_output_routing { * @routes: array of CRTC to output routes, indexed by output (RCAR_DU_OUTPUT_*) * @num_lvds: number of internal LVDS encoders * @dpll_mask: bit mask of DU channels equipped with a DPLL + * @lvds_clk_mask: bitmask of channels that can use the LVDS clock as dot clock */ struct rcar_du_device_info { unsigned int gen; @@ -67,6 +68,7 @@ struct rcar_du_device_info { struct rcar_du_output_routing routes[RCAR_DU_OUTPUT_MAX]; unsigned int num_lvds; unsigned int dpll_mask; + unsigned int lvds_clk_mask; }; #define RCAR_DU_MAX_CRTCS 4 diff --git a/drivers/gpu/drm/rcar-du/rcar_du_group.c b/drivers/gpu/drm/rcar-du/rcar_du_group.c index 5966d94..15dbef3 100644 --- a/drivers/gpu/drm/rcar-du/rcar_du_group.c +++ b/drivers/gpu/drm/rcar-du/rcar_du_group.c @@ -93,6 +93,54 @@ static void rcar_du_group_setup_defr8(struct rcar_du_group *rgrp) rcar_du_group_write(rgrp, DEFR8, defr8); } +static void rcar_du_group_setup_didsr(struct rcar_du_group *rgrp) +{ + struct rcar_du_device *rcdu = rgrp->dev; + struct rcar_du_crtc *rcrtc; + unsigned int num_crtcs = 0; + unsigned int i; + u32 didsr; + + /* + * Configure input dot clock routing with a hardcoded configuration. If + * the DU channel can use the LVDS encoder output clock as the dot + * clock, do so. Otherwise route DU_DOTCLKINn signal to DUn. + * + * Each channel can then select between the dot clock configured here + * and the clock provided by the CPG through the ESCR register. + */ + if (rcdu->info->gen < 3 && rgrp->index == 0) { + /* + * On Gen2 a single register in the first group controls dot + * clock selection for all channels. + */ + rcrtc = rcdu->crtcs; + num_crtcs = rcdu->num_crtcs; + } else if (rcdu->info->gen == 3 && rgrp->num_crtcs > 1) { + /* + * On Gen3 dot clocks are setup through per-group registers, + * only available when the group has two channels. + */ + rcrtc = &rcdu->crtcs[rgrp->index * 2]; + num_crtcs = rgrp->num_crtcs; + } + + if (!num_crtcs) + return; + + didsr = DIDSR_CODE; + for (i = 0; i < num_crtcs; ++i, ++rcrtc) { + if (rcdu->info->lvds_clk_mask & BIT(rcrtc->index)) + didsr |= DIDSR_LCDS_LVDS0(i) + | DIDSR_PDCS_CLK(i, 0); + else + didsr |= DIDSR_LCDS_DCLKIN(i) + | DIDSR_PDCS_CLK(i, 0); + } + + rcar_du_group_write(rgrp, DIDSR, didsr); +} + static void rcar_du_group_setup(struct rcar_du_group *rgrp) { struct rcar_du_device *rcdu = rgrp->dev; @@ -110,21 +158,7 @@ static void rcar_du_group_setup(struct rcar_du_group *rgrp) if (rcar_du_has(rgrp->dev, RCAR_DU_FEATURE_EXT_CTRL_REGS)) { rcar_du_group_setup_defr8(rgrp); - - /* - * Configure input dot clock routing. We currently hardcode the - * configuration to routing DOTCLKINn to DUn. Register fields - * depend on the DU generation, but the resulting value is 0 in - * all cases. - * - * On Gen2 a single register in the first group controls dot - * clock selection for all channels, while on Gen3 dot clocks - * are setup through per-group registers, only available when - * the group has two channels. - */ - if ((rcdu->info->gen < 3 && rgrp->index == 0) || - (rcdu->info->gen == 3 && rgrp->num_crtcs > 1)) - rcar_du_group_write(rgrp, DIDSR, DIDSR_CODE); + rcar_du_group_setup_didsr(rgrp); } if (rcdu->info->gen >= 3)